Shaft drive transmission and coupling rod

ABSTRACT

An inventive coupling rod ( 12, 42 ) for a shaft drive rod assembly ( 11 ) of a heald shaft ( 1 ) is designed as an open bent sheet metal component. The cross-section of this component is uniform along the length of the coupling rod ( 12, 42 ), with the exception of its ends ( 13, 14 ). Such a coupling rod ( 12, 42 ) permits the construction of shaft drive rod assemblies which are cost-effective and light-weight, and are suitable for the high operating speeds of the weaving machine.

BACKGROUND OF THE INVENTION

The invention relates to a coupling rod for a shaft drive transmission for a heald shaft, as well as to such a shaft drive transmission.

Referring to document WO 2004/057078 A2, a shaft drive transmission for a heald shaft has been known. The shaft drive transmission is used to effect the rapid movement of the heald shaft. In so doing, the shaft drive transmission translates an approximate back-and-forth movement of a shaft drive into the up-and-down movement used for driving the heald shaft. To achieve this, the shaft drive transmission has three angle levers arranged in a row, each of said levers having two arms. The arms of the angle levers extending downward from a fulcrum are connected to each other by coupling rods. As opposed to this, the arms of the angle levers extending approximately in horizontal direction are connected to the lower shaft rod of the rectangular heald shaft by means of push rods. Via a connecting bar, the aforementioned back-and-forth movement is input into one end of the angle lever, so that the heald shaft can be moved up and down as desired.

As the weaving speed is increased, the heald shafts must be moved faster. Correspondingly, the coupling rods must transmit pulling and pushing forces which also increase, despite the otherwise attempted, and frequently also achieved, weight reduction of the heald shafts. The pulling and pushing forces are of a rocking nature. In addition, the coupling rods do not perform a strict axial movement. On their ends, said coupling rods are connected to the arms of the angle levers and are thus suspended in a pendulum fashion. During rapid movement, a lifting and lowering motion component is created, thus potentially resulting in rocking flexural load being applied to the coupling rods.

Despite the increasing demands on the load capacity, the manufacturing costs for the shaft drive transmission are to be lowered. This objective also involves the coupling rod.

Considering this, it is the object of the invention to provide a shaft drive transmission and, in particular, a coupling rod, which, during operation, can withstand high dynamic loads and are easy to manufacture.

SUMMARY OF THE INVENTION

This object is achieved with the coupling rod in accordance with Claim 1.

The inventive coupling rod for a shaft drive transmission of a heald shaft is designed as an open formed sheet metal component. Preferably, it has a cross-section—aside from potentially subsequently applied cutouts—that is the same along the entire length of the coupling rod. Therefore, said coupling rod can be manufactured by simple sheet metal forming processes, for example, a canting process, roll forming process, and similar processes. This provides for high manufacturing reliability at low cost.

The open formed sheet metal component can combine high buckling stiffness with low weight. This opens the possibility of being able to produce high machine speeds in a simple and cost-effective manner.

The cross-section of the open formed sheet metal component preferably encloses an area having a vertically measured height in operative position that is greater than its horizontally measured width in operative position. Preferably, the width does not exceed the width of a shaft rod. The profile is open; i.e. the edges of the rod-like formed sheet metal component manufactured of a sheet metal strip, for example by profile rolling, are connected to each other in an at least not continuous manner. This imparts the coupling rods with some flexibility, which may have an advantageous effect.

The profile of the formed sheet metal component extends from one end to the other end and creates a straight rod-like element. Connecting means for the angle levers of a shaft drive rod assembly can be provided at the ends. For example, the connecting means can be connection openings, which are provided in the preferably flat lateral walls of the coupling rod and, which, if desired, may be provided with a funnel-shaped edge. If necessary, one or more additional connection locations may be provided, whereby these are arranged between the ends of the formed sheet metal element. Such connecting locations can be used for connecting additional angle levers, guide or carrier tabs, or the like.

The ends of the element preferably have a forked configuration. The forked ends seamlessly adjoin, in one piece, the otherwise formed sheet metal profile. These ends are produced in that, the formed sheet metal profile having a continuously consistent cross-section in longitudinal direction is provided with cutouts. This preferred embodiment can be manufactured in a simple manner, and is sturdy and durable.

The cross-section of the formed sheet metal profile, when the coupling rod is arranged in a use-specific manner, has a height that is greater than its width. Therefore, a back wall or strip wall that is preferably provided on the coupling rod is narrower than the lateral walls. Due to this measure, the connection opening provided for the connection of the angle levers can be provided with a diameter which is at least as large as the width of the strip wall. The connection openings can thus include hinge pins having a diameter that is large enough that the bearing stress occurring at the edge of the connection opening does not result in excessive wear, even in instances of highly dynamic operation.

Preferred embodiments of the coupling rod have side walls with bent edges. Preferably, these edges are bent inward (i.e., toward each other), or even outward (i.e., away from each other), and provide the coupling rod—while maintaining a certain elasticity—with sufficient rigidity, in particular with sufficient buckling stiffness. Preferably, the edges are arranged at a distance from each other. They may also be in contact with each other, however, they are not welded to each other, or at least not welded to each other along the entire length. It is possible to provide, in one of the joints defined by two edges, an air gap or even a select material, for example, a damping material. This may be an adhesive, a plastic material, such as, for example an elastomer, or the like. Due to the absent continuous metal joint and the at least existing flexibility of this joint connection, such formed sheet metal profiles are also referred to as “open profiles”. Such open profiles can be filled with a filler, such as, for example, a plastic material or a foamed material.

The coupling rod provides the shaft drive rod assembly with a lower total weight and a high load-bearing capacity, while, at the same time, manufacturing costs are low.

Details of advantageous embodiments of the invention are the subject matter of the claims, drawings or the description.

The drawing shows exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic front view of a heald shaft, as well as a shaft drive rod assembly with a coupling rod in accordance with the invention.

FIG. 2 is a side view of the coupling rod of FIG. 1.

FIG. 3 is a plan view of the coupling rod of FIG. 2.

FIG. 4 is a cross-section of the coupling rod of FIG. 3.

FIGS. 5 through 13 are cross-sections of various modified embodiments of the coupling rod.

FIG. 14 show a further embodiment of a shaft drive rod assembly for a heald shaft with two coupling rods.

FIG. 15 shows a shaft drive rod assembly for a heald shaft with an intermediately supported coupling rod.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a heald shaft 1 which is used in a weaving machine for shed formation. To achieve this, healds 4 are held between the shaft rod 2, arranged in horizontal direction when in use, and the lower shaft rod 3 on not specifically illustrated corresponding heald-supporting tracks, said healds 4 having at least one eyelet. A cluster of warp threads passes through this eyelet of the healds. Another cluster of warp threads passes between the healds. These warp threads are held in at least one additional heald shaft 1. The movements of the heald shafts 1 can be controlled independently of each other. As a result of the up-and-down movement as indicated by an arrow in FIG. 1, the warp threads of one cluster are vertically offset with respect to the warp threads of the other cluster, thus forming a shed. The weft thread is input in a direction transverse to all the warp threads.

The heald shaft 1 is associated with lateral supports 5, 6, which hold the shaft rods 2, 3 at a fixed distance from each other, forming a rectangular frame with said shaft rods. This rectangular frame as a whole is moved vertically upward and downward during the shed formation, i.e., up and down. In order to drive the heald shaft 1, a shaft drive 7 is provided and symbolized only by a rocker 8 and by a connecting rod 9 which imparts the rocker 8 with a rocking motion about a fulcrum 10. This rocking motion is indicated in FIG. 1 by a corresponding arrow. The rocker 8 represents the output of the shaft drive 7.

In order to transmit the drive motion from the rocker 8 to the heald shaft 1 and to translate the drive motion into an up-and-down motion of the heald shaft 1, a shaft drive rod assembly 11 is provided. The latter comprises a coupling rod 12, which preferably is arranged parallel to the shaft rods 2, 3 beneath the heald shaft 1. On both its ends 13, 14, it is connected to respectively one downward pointing arm 15, 16 of an angle lever 17, 18. Both angle levers 17,18 are supported such that they can be pivoted about a stationary respective fulcrum 19, 20, which, for example, is designed as a bearing pin on a not specifically illustrated frame. Another arm 21, 22 extents from each fulcrum 19, 20 away from the arm 15, 16 at an approximately right angle. Push rods 23, 24 are hinged to the ends of the arms 21, 22, said push rods being connected to the heald shaft 1. For example, they are connected to the lateral supports 5, 6 in order to input the up-and-down drive movement into the shaft rod at that point. Alternatively, the angle levers 17, 18 can be connected to the shaft rod 3 via corresponding tabs.

FIGS. 2 through 4 show the coupling rod 12 by itself, with reference now being made thereto. The coupling rod 12 having a length of, for example, one meter (1 m) or being significantly longer, is designed as a formed sheet metal component, in particular, as a bent sheet metal component. Said component may be produced by canting, roll forming or any other suitable sheet metal forming process and has a consistent cross-section along its entire length, for example, as in FIG. 4. The coupling rod 12 is then made up of two lateral walls 25, 26, which, when the coupling rod 12 is in its operative position, are oriented in vertical direction and are continuous from end 13 to end 14. The lateral walls 25, 26 are kept parallel at a distance from each other and are connected to each other by means of a strip wall 27 that seamlessly adjoins the lateral walls 25, 26 along the bending lines 28, 29. As illustrated, the strip wall 27 may be flat or, if desired, be convex and provided with longitudinally extending ribs or the like. The same applies to the lateral walls 25, 26.

At the ends 13, 14, the strip wall 27 is cut out so that cutouts 30, 31 are formed. The bending lines 28, 29 end at the cutouts 30, 31 and are arranged in straight extension relative to the exposed edges of the lateral walls 25, 26 at that point. These lateral walls form free-standing flaps that extend parallel to each other and provide the profiled element with forked ends 13, 14.

On the ends 13, 14, the lateral walls 25, 26 are provided with openings 32, 33, 34, 35 that form the connection openings for the angular levers 17, 18. The openings 32, 33, 34, 35 provided on the ends 13, 14 are in alignment parallel to each other. The opening 32 is in alignment with the opening 33, and the opening 34 with the opening 35. All openings are provided with inward-directed drafts 36, 37, 38, 39 having the shape of a truncated cone, said drafts holding an angle lever held between the lateral walls at a distance with respect to the lateral wall and centering a potential bearing, for example, a ball bearing.

On their edge away facing away from the strip wall 27, the lateral walls 25, 26 are provided with bent edges 40, 41. Preferably, these edges are bent inward at 180°, i.e., first toward each other and then toward the strip wall 27. In so doing, they preferably are at a distance parallel to the respective lateral wall 25, 26, which they adjoin. It is also possible to bend the edges 40, 41, after the previously described bending, again toward each other and then again toward the lateral wall 25, 26. Then, the edges 40, 41 have additional bending lines 27, 28. The length of the edges 40, 41, which is to be measured parallel to the strip wall 27 and the lateral walls 25, 26, essentially corresponds to the length of the strip wall 27. The bend edges 40, 41 end on the cutouts 30, 31 in order to allow free passage to the angle levers. Alternatively, the bent edges 40, 41—provided there is enough free space—can also be formed into the region of the cutouts 30, 31 and be adapted to the length of the lateral walls 25, 26. They may be pressed flat in the cutouts 30, 31 against the lateral walls 25, 26, should this be required. Preferably, the edges 40, 41 have a consistent width, i.e., they form a strip having a rectangular contour. The edges 40, 41 may have different heights. For example, it is possible for the height of the edges 40, 41 to substantially correspond to the height of the lateral walls 25, 26. If desired, it is possible to deviate from this shape. Furthermore, the shaft drive rod assembly 11 comprises another coupling rod 42 that connects the rocker 8 to the angle lever 17. The coupling rod 42 can also be connected to the shaft drive rod assembly in a different manner. Essentially, this rod has the same configuration as the coupling rod 12.

The shaft drive rod assembly is disposed to operate as follows:

When in use, the rocker 8 performs the rocking motion as indicated in FIG. 1. Via the coupling rod 42, this motion is transmitted to an angle lever 17, which, as a result, performs a back-and-forth rocking motion about the fulcrum 29. The coupling rod 12, which is connected to the lower arm 15, transmits this motion—as indicated by an arrow 43 in FIG. 1—to the angle lever 18. Consequently, the two angle levers 17, 18 rock back and forth in a synchronous manner. Using their arms 21, 22, they move the heald shaft 1 up and down. In order to move the angle levers 17, 18, the coupling rod 12 transmits pushing and pulling forces from the arm 15 to the arm 16, and vice versa. In so doing, said rod moves mainly in horizontal direction and, as indicated by the arrow 43, also with a certain vertical component. A transverse component (indicated perpendicular to the plane of projection in FIG. 1) does not occur. The coupling rod 12 is connected to the arms 15, 16 via pivot hinges, whereby their hinge axes extend parallel to each other, transverse to the coupling rod 12 as in FIG. 1, and perpendicular to the plane of projection. Despite the strict pushing and pulling loads and the absent transverse acceleration, transverse vibrations may be triggered. The buckling stiffness of the coupling rod 12 must is sufficient in order to be able to withstand such bending vibrations. This is mainly done by the edges 40, 41.

FIGS. 5, 6 and 7 show embodiments of the coupling rod 12, 42 configured as the coupling rods 112, 212, 312, which have essentially the same design as the above-described coupling rod 12, 42. These rods are different regarding the size and location of the bent edges 140, 141, 240, 241, 340, 341. As is obvious, viewing the coupling rod 112, it is advantageous if the edges 140, 141 have back sections 144, 145 that are located on one common plane and are oriented parallel to the strip wall 127. These contribute substantially to the stiffening. A gap 146—which remains open—may be provided between the additional folded-over parts of the edge 140, 141.

As is shown by FIG. 6, the back sections 244, 245 may also have a larger size, so that the gap 246 becomes narrower. However, also in this case, the edges 240, 241 do not contact each other. Also, the gap 346 may be considerably wider, as illustrated by FIG. 7 with reference to the coupling rod 312 and the edges 340, 341.

As shown by FIG. 8 with reference to a coupling rod 412, the edges 440, 441 can also be bent outward by 180° and not only inward by 180°, as mentioned above. In so doing, the gap 446 extends across the entire inside width of the coupling rod 412, this essentially corresponding to the width of the strip wall 427. This embodiment is suitable for those embodiments requiring the edges 440, 441 to extend into the connecting region at the ends 13, 14, and thus the edges need not be cut off.

As shown by FIG. 9 with reference to a coupling rod 512, the lateral walls 525, 526 can not only be arranged parallel to each other but also at an angle with respect to each other and can thus be arranged at an acute angle with respect to the strip wall 527. As illustrated, the edges 540, 541 can be bent outward or also be bent inward, as shown by FIGS. 5, 6 and 7. In so doing, said edges may be bent by 180° or, as shown by FIG. 10 with reference to the coupling rod 612, be also bent by a smaller angle. The edges of the edges 640, 641, again, are not joined. Thus a gap 646 is formed.

Whereas all the above-described embodiments comprise coupling rods with edges that are at a distance from each other, FIGS. 11 through 13 illustrate a class of coupling rods 712, 812, 912 with edges 740, 741, 840, 841, 940, 941, with or without gap, that are designed so as to lie flat against each other. Referring to FIG. 13, the resultant joint may extend parallel to the strip wall 927; referring to FIG. 11, at an acute angle with respect to the strip wall 727; and, referring to FIG. 12, extend beyond a bending line into the region of the lateral wall 825. The dividing joint may remain open as an air gap. Furthermore, it may be joined—at some points—by rivets, by spot-welding or be joined—along part of its length or along its entire length—by an adhesive or damping material. It is still considered an “open” profile, because there is no continuous elastic joint along the entire length between the edges 740, 741, 840, 841, 940, 941. The same applies to the coupling rods of FIGS. 4 through 10, whereby their respective edges are separated by an open gap. All the shown coupling rods may be filled with a dimensionally stable light-weight material, such as, for example, PUR foam.

FIG. 14 shows the embodiment of a shaft drive rod assembly 11′, which has two coupling rods 12 a, 12 b, instead of the so-far described coupling rod 12. Basically, these coupling rods have the same configuration. They may be different regarding their length, should this be necessary. In addition to the angle levers 17, 18, another angle lever 17 a is provided, at which the ends of the coupling rods 12 a, 12 b are connected to each other and which contributes to the drive of the heald shaft 1. Other than that, the above description applies analogously.

Furthermore, it is possible, as shown by FIG. 15, to support particularly long coupling rods 12′ at one or more points. To achieve this, tabs 45 that can be pivoted about a fulcrum 44 can be used, said tabs having a length corresponding to the arm 15, 16. In order to connect the tab 45 to the coupling rod, said rod may be provided with a connecting piece 46. This may be connected to the strip wall 27 by means of appropriate mechanical connecting means, such as rivets, screws, spot-welded seams, adhesive areas, or the like. Furthermore, it may extend through a cutout in the strip wall into the intermediate space between the lateral walls and, as shown by FIG. 15, be held by a rivet 47, 48.

An inventive coupling rod 12, 42 for a shaft drive rod assembly 11 of a heald shaft 1 is designed as an open bent sheet metal component. The cross-section of this component is uniform along the length of the coupling rod 12, 42, with the exception of its ends 13, 14. Such a coupling rod 12, 42 permits the construction of shaft drive rod assemblies which are cost-effective and light-weight, and are suitable for the high operating speeds of the weaving machine.

It will be appreciated that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

List of Reference Numbers:

-   1 Heald shaft -   2 Shaft rod -   3 Shaft rod -   4 Healds -   5 Lateral support -   6 Lateral support -   7 Shaft drive -   8 Rocker -   9 Connecting rod -   10 Fulcrum -   11, 11′ Shaft drive rod assembly -   12, 12 a, 12 b, 12′ Coupling rod -   13 End -   14 End -   15 Arm -   16 Arm -   17, 17 a Angle lever -   18 Angle lever -   19 Fulcrum -   20 Fulcrum -   21 Arm -   22 Arm -   23 Push rod -   24 Push rod -   25 Lateral wall -   26 Lateral wall -   27 Strip wall -   28 Bending line -   29 Bending line -   30 Cutout -   31 Cutout -   32 Opening -   33 Opening -   34 Opening -   35 Opening -   36 Draft -   37 Draft -   38 Draft -   39 Draft -   40 Edge -   41 Edge -   42 Coupling rod -   43 Arrow -   44 Fulcrum -   45 Link -   46 Connecting piece -   47 Rivet -   48 Rivet -   112 Coupling rod -   127 Strip wall -   140 Edge -   141 Edge -   144 Back section -   145 Back section -   146 Gap -   112, 212 Coupling rod -   240 Edge -   241 Edge -   244, 245 Back section -   246 Gap -   312 Coupling rod -   340 Edge -   341 Edge -   346 Gap -   412 Coupling rod -   440 Edge -   441 Edge -   446 Gap -   427 Strip wall -   512 Coupling rod -   525 Lateral wall -   526 Lateral wall -   527 Strip wall -   540 Edge -   541 Edge -   612 Coupling rod -   640 Edge -   641 Edge -   646 Gap -   712 Coupling rod -   727 Strip wall -   740 Edge -   741 Edge -   812 Coupling rod -   825 Lateral wall -   826 Lateral wall -   840 Edge -   841 Edge -   912 Coupling rod -   927 Strip wall -   940 Edge -   941 Edge 

1. Coupling rod (12, 42) for a shaft drive rod assembly of a heald shaft (1), configured as an open formed sheet metal component.
 2. Coupling rod in accordance with claim 1, characterized in that the coupling rod (12, 42) has two ends (13, 14), between which extends a straight element formed by the formed sheet metal profile.
 3. Coupling rod in accordance with claim 2, characterized in that the coupling rod (12, 42) has at least two lateral walls (25, 26) arranged at a distance from each other, said walls extending parallel to a longitudinal axis that extends from the one end (13) to the other end (14).
 4. Coupling rod in accordance with claim 3, characterized in that the coupling rod (12) has, at least on its two ends (13, 14), cutouts (30, 31) through which respectively one arm (15, 16) of an angle lever (17, 18) to be connected between the two side walls (25, 26) can be inserted.
 5. Coupling rod in accordance with claim 2, characterized in that the element is forked on its two ends (13, 14).
 6. Coupling rod in accordance with claim 3, characterized in that each of the two lateral walls has on the ends (13, 14) of the coupling rod (12) at least one connection opening (32, 33, 34, 35), whereby the connection openings (32, 33, 34, 35) of the two lateral walls (25, 26) are in paired alignment.
 7. Coupling rod in accordance with claim 1, characterized in that the formed sheet metal component has at least one strip wall (27) and at least two lateral walls (25, 26) which are connected to each other by the strip wall (27).
 8. Coupling rod in accordance with claim 7, characterized in that the lateral walls (25, 26) have a height to be measured perpendicular to the strip wall (27), said height being greater than the width of the strip wall (27) to be measured perpendicular to the lateral walls (25, 26).
 9. Coupling rod in accordance with claim 7, characterized in that the lateral walls (25, 26) subtend respectively the same maximum angle of 90° with the strip wall (27).
 10. Coupling rod in accordance with claim 7, characterized in that the lateral walls (25, 26) have respectively one edge (40, 41) which is bent at least along a bending line relative to the remaining lateral wall (25, 26).
 11. Coupling rod in accordance with claim 10, characterized in that the edges (40, 41) of the lateral walls (25, 26) are bent toward each other.
 12. Coupling rod in accordance with claim 10, characterized in that the edges (540, 541) of the lateral walls (525, 526) are bent away from each other.
 13. Coupling rod in accordance with claim 10, characterized in that the edges (40, 41) of the lateral walls (25, 26) define a distance between each other.
 14. Coupling rod in accordance with claim 10, characterized in that the edges (840, 841) of the lateral walls (825, 826) are arranged so as to abut against each other.
 15. Coupling rod in accordance with claim 10, characterized in that the edges (840, 841) of the lateral walls (825, 826) are not joined to each other.
 16. Coupling rod in accordance with claim 10, characterized in that the edges (840, 841) of the lateral walls (825, 826) are joined to each other.
 17. Coupling rod in accordance with claim 10, characterized in that the edges (840, 841) of the lateral walls (825, 826) are joined to each other by means of a plastic material and/or by an adhesive.
 18. Coupling rod in accordance with claim 10, characterized in that the coupling rod (12′) has, at a point located between its ends (13, 14), a connecting device (46) for a support guide (45).
 19. Shaft drive rod assembly (11) for a heald shaft (1) comprising at least two deflecting means (17, 18) for translating a horizontal back-and-forth movement into an up-and-down movement, whereby the deflecting means (17, 18) are connected to the heald shaft (1); at least one coupling rod (12, 42) in accordance with claim 1, said rod being connected to the deflecting means (17, 18) in order to transmit the back-and-forth movement between the deflecting means (17, 18).
 20. Shaft drive rod assembly in accordance with claim 19, characterized in that the deflecting means (17,18) are composed of respectively one angle lever having a fulcrum (19, 20) and two arms (15, 21; 16, 22) extending therefrom.
 21. Shaft drive rod assembly in accordance with claim 20, characterized in that the angle levers (17, 18) are connected to the heald shaft (1) by means of push rods (23, 24) which each adjoin an arm (21, 22) of each angle lever (17, 18) and are pivotally connected to said arm. 